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<title>16.6.1 Dl Objects </title>
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<h2><a name="SECTION0018610000000000000000"></a><a name="dl-objects"></a>
<br>
16.6.1 Dl Objects 
</h2>

<p>
Dl objects, as returned by <tt class="function">open()</tt> above, have the
following methods:

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-3539' xml:id='l2h-3539' class="method">close</tt></b>(</nobr></td>
  <td><var></var>)</td></tr></table></dt>
<dd>
Free all resources, except the memory.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-3540' xml:id='l2h-3540' class="method">sym</tt></b>(</nobr></td>
  <td><var>name</var>)</td></tr></table></dt>
<dd>
Return the pointer for the function named <var>name</var>, as a number, if
it exists in the referenced shared object, otherwise <code>None</code>. This
is useful in code like:

<p>
<div class="verbatim"><pre>
&gt;&gt;&gt; if a.sym('time'): 
...     a.call('time')
... else: 
...     time.time()
</pre></div>

<p>
(Note that this function will return a non-zero number, as zero is the
<tt class="constant">NULL</tt> pointer)
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-3541' xml:id='l2h-3541' class="method">call</tt></b>(</nobr></td>
  <td><var>name</var><big>[</big><var>, arg1</var><big>[</big><var>, arg2...</var><big>]</big><var></var><big>]</big><var></var>)</td></tr></table></dt>
<dd>
Call the function named <var>name</var> in the referenced shared object.
The arguments must be either Python integers, which will be 
passed as is, Python strings, to which a pointer will be passed, 
or <code>None</code>, which will be passed as <tt class="constant">NULL</tt>.  Note that 
strings should only be passed to functions as <tt class="ctype">const char*</tt>, as
Python will not like its string mutated.

<p>
There must be at most 10 arguments, and arguments not given will be
treated as <code>None</code>. The function's return value must be a C
<tt class="ctype">long</tt>, which is a Python integer.
</dl>

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<span class="release-info">Release 2.5.1, documentation updated on 18th April, 2007.</span>
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